两种双频光栅剖面术的理论分析与性能比较

Comparison of Two Two-frequency Gratings Used for Three-dimensional Surface Profilometry

Li和Yasuyuki先后提出了两种应用于三维面形测量的双频光栅剖面术,这两种双频光栅均是将两种不同频率的条纹模式复合在同一个光栅上,但光栅复用的原理并不相同。就这两种双频光栅剖面术的原理、频域分析和三维重建的计算效率进行了详细的比较。分析结果表明,Yasuyuki双频光栅只适用于相移剖面术,不适用于傅立叶变换剖面术;而Li双频光栅两种方法都适用。无论是理论分析还是计算机模拟都表明,Li双频光栅剖面术的三维重建的计算效率比Yasuyuki高得多。

Li and Yasuyuki successively proposed two different two-frequency gratings used for three-dimensional surface profilometry. Two gratings are both made of two sets of fringes with different frequencies, but their complex principles are different. In this paper, we compared and analyzed these two gratings on the aspects of principles, spectrums and computation efficiency of three-dimensional reconstruction. From the theoretical analysis, we attained the different ranges of application of the two gratings, which can provide theoretical basis for the choosing of two-frequency gratings profilometry. The results of the theoretical analysis show that Yasuyuki's two-frequency grating is only fit for Phase Measurement Profilometry, while Li's is not only fit for Phase Measurement Profilometry, but also fit for Fourier Transform Profilometry. Both the theoretical analysis and the simulation show that the theoretical efficiency of three-dimensional reconstruction from Li's formula is much higher than that from Yasuyuki's one.